Grand Canyon, Clay Tank Castle, first ascent. Andy Martin, while searching topo maps for high points, discovered that the second highest butte in the Canyon was an unnamed, unclimbed redwall butte in the far west end of the Grand Canyon. He told me about it, and a friend flew me over it for scouting. I contacted Aaron Tomasi to see if he'd climb it with me. He said sure, so I got a permit from Grand Canyon National Park, and in May we rafted the 55-mile lower section of the Colorado River in the Canyon from Diamond Creek to get to the base of what we called Clay Tank Castle. It took a lot of class 4 route-finding to get to the last redwall section, the north fin. Due to the poor rock, I ended up free-soloing the last 200 feet or so, maybe 5.6 at the worst, but the exposure was XXX for a good 100 feet.
This castle, north-northwest of Clay Tank Canyon (Spencer Canyon quad, 29N13W), may have been the last unclimbed butte in Arizona (and even the Lower 48), with over 1,000 feet of shoulder/prominence (the elevation difference between the summit and the lowest contour that encircles it and no higher summit). A map of the butte is at: http://www.topozone. com/map.asp?z=12&n=3970405&e=257560&s=25&size=m&symshow [try zooming out to a smaller scale to find the butte.—Ed.].
Tom Martin, River Runners For Wilderness